1. Field of the Invention
The present invention relates to a method for coding video information, and more particularly, to a method which represents that the video information has been encoding or non-encoding according to certain parameters by extending a video information field. Furthermore, the present invention relates to a method of reducing the amount of video bits, by which a method of representing encoding or non-encoding by the extension of an information field for representing encoding or non-encoding can be applied to an error allowable mode, and by which the amount of bits depending on the characteristics of video information to be coded can be reduced.
2. Description of Related Art
In the case of a block-based codec, an object-based codec, or a shape-based codec, a general technique for encoding a moving picture is as follows. A motion vector designates a block of a previous frame which is most similar to a current block, and a real value or a modified value (e.g., DCT) with respect to the difference between real data of the current and previous blocks are encoded to produce data, so that a block is encoded.
In H.263 and MPEG-4, a “COD (code)” field is used to designate whether a motion vector and a DCT are encoded in the bit stream.
FIG. 1 is a conceptual view showing a method of representing encoding and non-encoding in a general bit stream.
As shown in FIG. 1, whether a motion vector MV and a DCT coefficient are encoded or not is represented by a one-bit value of a COD field. That is, if the bit of the COD field is “0”, it indicates that the MV and the DCT are encoded, but if the bit thereof is “1”, it indicates that they are not encoded.
However, when the encoding or non-encoding of a block is designated by using the COD field, this information is represented by only one bit. Thus, in some cases when this one bit is used in a channel having an error, the entire information is easily misinterpreted due to only the error of one bit.
Also, in the case of an image motion on a predetermined background, only the motion vector (MV) is required during actual encoding and the difference value (DCT) is not needed. In the conventional technique, the difference value (DCT) is also encoded to thereby cause an increase in the amount of bits.